import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        int size = 4;//数组长度为4；
        Scanner num = new Scanner(System.in);
        int[] arrays = new int[size];
        for (int i = 0; i < size; i++) {
            arrays[i] = num.nextInt();
        }
        int max = arrays[0];//假设第一个元素为最大值
        for (int i = 0; i < arrays.length; i++) {
            if(arrays[i] > max){
                max = arrays[i];
            }
        }
        System.out.println(max);
    }
}